In many types of self-contained networks, for example the electrical networks of automotive vehicles, it is customary to wind the generator to include a compound winding. The compound winding has load current flowing therethrough. Additionally, a voltage regulator is provided to control the output voltage of the generator to an appropriate level so that the battery, which floats on the network, is maintained in a continuous state of charge. If the output voltage of the alternator drops, the voltage regulator is controlled to conduction to permit current flow through an exciter field winding. This causes a rise in the output voltage of the alternator and, when the output voltage thereof exceeds a predetermined level, the voltage regulator causes current to the exciter field winding to be interrupted, so that the voltage will drop. This cycle repeats in short intervals, thus maintaining the output voltage of the alternator essentially constant. The voltage of the generator, thus, is maintained at the predetermined level, independent of the speed of the alternator or the load placed thereon, or the load state of the battery connected to the network. In high-power alternators, an additional compound winding is customary, so that the currents through the shunt field exciter windings can be held at a lower level. This permits use of voltage regulators of lower current carrying capacity, and hence lesser switching losses in the overall system. The use of the compound winding permits higher loading of the alternator, since the load current flows through the compound winding, thus increasing the excitation as the load on the alternator increases. Compound windings, however, when used in vehicular applications in which the alternator is driven at widely varying speeds have the disadvantage that at extremely high speeds, with even moderate loading on the alternator, the alternator can be excessively excited so that, even if the shunt-connected voltage regulator has disconnected excitation energy to the shunt winding, the output voltage of the alternator rises to a level which may cause damage to the battery connected to the network.